Tibiofemoral Osteoarthritis Research Articles

Immediate and short-term effects of real-time knee adduction moment feedback on the peak and cumulative knee load during walking.

The peak external knee adduction moment (pKAM), KAM impulse, and peak knee flexion moment (pKFM) during gait are important loading variables in medial tibiofemoral osteoarthritis. We evaluated the effects of gait modification, using real-time pKAM visual feedback, on pKAM, KAM impulse, and pKFM; and whether participants could maintain the KAM-reducing gait after feedback removal. Eleven healthy individuals performed a series of walking trials on a split-belt instrumented treadmill under four conditions of Baseline, Feedback, No Feedback Early, and No Feedback Late. Guided by real-time feedback of pKAM, they modified their gait patterns to lower pKAM by 20%. Three-dimensional joint kinematics/kinetics during each walking condition were recorded by a 12-camera motion capture system and the instrumented treadmill. Change in each knee loading parameter from baseline across conditions was assessed using one-way repeated-measures analysis-of-variances. In the feedback limb, successful 20% reductions from baseline in pKAM and KAM impulse were achieved across all three conditions. There was a trend for concomitant pKFM increases, partially attenuating the beneficial effects of pKAM reduction. A carry-over effect of KAM reduction in the non-feedback limb was noted. The altered gait patterns were participant-specific and multi-modal; each participant reported a combination of two to three gait modification strategies used for pKAM reduction. Toe-in and medial foot contact were the most reported strategies. The findings support the real-time pKAM visual feedback as a tool for individualized gait modification to reduce knee load. Future studies to evaluate its effectiveness in persons with or at risk for medial knee osteoarthritis is warranted. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:397-404, 2018.

Low-impact sports activities are feasible after meniscus transplantation: a systematic review

To determine sports activities achieved after meniscus transplantation and if associations exist between sports activity levels and transplant failure or progression of tibiofemoral osteoarthritis (OA). A systematic search was performed using PubMed and Cochrane online databases. Inclusionary criteria were English language, clinical trials published from 1996 through May 2017, minimum 2years of follow-up, and sports activity data reported. Twenty-eight studies were included in which 1521 menisci were implanted into 1497 patients. The mean age was 34.3±6.7years, and the mean follow-up was 5.0±3.7years. Details on sports activities were provided in 7 studies (285 patients) that reported 70-92% of patients returned to a wide variety of sports activities. Mean Tegner activity scores were reported in 24 investigations. The mean score was <5 in 58% of these studies, indicating many patients were participating in light recreational activities. There was no association between mean Tegner scores and transplant failure rates. A moderate correlation was found between failure rates and mean follow-up time (R=0.63). The effect of sports activity levels on progression of tibiofemoral OA could not be determined because of limited data. Only two studies determined whether symptoms occurred during sports activities; these reported 1/38 (3%) and 5/69 (7%) patients had knee-related problems. It appeared that the majority of individuals returned to low-impact athletic activities after meniscus transplantation. The short-term follow-up did not allow for an analysis on the effect of return to high-impact activities on transplant failure rates or progression of OA. IV.

Long-Lasting Hyperalgesia Is Common in Patients Following Patella Fractures.

The objective was to investigate the long-term development of pain and hyperalgesia after patella fractures. The secondary objective was to report the association between tibiofemoral and patellofemoral osteoarthritis, pain, and hyperalgesia. The study used a cohort design. Patients who were treated for patella fractures between January 2006 and December 2009 were identified. Patients age 20 to 78 years were included. The main outcome was the pain pressure threshold (PPT). Moreover, visual analog scale (VAS) for pain, radiological outcomes of patellofemoral and tibiofemoral osteoarthritis, and the pain subscale of the WOMAC and EQ-5D questionnaires were used. Forty-nine patients were included, with a mean age of 53.9 years and a mean follow-up time of 8.5 years. The injured knee region showed significantly decreased PPT levels (P < 0.046), but decreases in PPT were not found for the forearm region (P = 0.24). The VAS score for the worst pain during the last 24 hours was reported, with a mean of 2.9 ± 2.4 cm. The EQ-5D-5L-pain scale was reported, with a mean score of 2.4 (95% confidence interval [CI] = 2.0-2.7). The WOMAC Pain score was reported, with a mean score of 3.9 (95% CI = 2.8-4.9). Moderate correlations were found between the VAS scores and PPT levels (R = 0.428, P = 0.002). Weak correlations were found between VAS scores and PPT levels for site 7 (forearm; R = 0.313, P = 0.03). The present study suggests that long-lasting local hyperalgesia following a patella fracture is common. No side-to-side difference at the forearms were observed, indicating that the observed local hyperalgesia was not part of a generalized sensitization.

Is the atrophic phenotype of tibiofemoral osteoarthritis associated with faster progression of disease? The MOST study.

To assess the associations of atrophic tibiofemoral osteoarthritis (OA) with progression of radiographic joint space narrowing (JSN) and magnetic resonance imaging (MRI)-defined progression of cartilage damage. Participants of the Multicenter Osteoarthritis (MOST) Study with available radiographic and MRI assessments at baseline and 30 months were included. The atrophic OA phenotype was defined as Osteoarthritis Research Society International (OARSI) grades 1 or 2 for JSN and grade 0 for osteophytes. Based on MRI, atrophic OA was defined as tibiofemoral (TF) cartilage damage grades ≥3 in at least 2 of 10 subregions with absent or tiny osteophytes in all TF subregions. Progression of JSN and cartilage loss on MRI, was defined as (1) no, (2) slow, and (3) fast progression. Co-variance and logistic regression with generalized estimated equations were performed to assess the association of atrophic knee OA with any progression, compared to non-atrophic OA knees. A total of 476 knees from 432 participants were included. There were 50 (10.5%) knees with atrophic OA using the radiographic definition, and 16 (3.4%) knees with atrophic OA using MRI definition. Non-atrophic OA knees more commonly exhibited fast progression of JSN and cartilage damage. Logistic regression showed that the atrophic phenotype of knee OA was associated with a decreased likelihood of progression of JSN and cartilage loss. In this sample, the atrophic phenotype of knee OA was associated with a decreased likelihood of progression of JSN and cartilage loss compared to the non-atrophic knee OA phenotype.

Association of diabetes mellitus and biochemical knee cartilage composition assessed by T2 relaxation time measurements: Data from the osteoarthritis initiative.

To investigate the association of the presence and severity of diabetes mellitus (DM) with articular cartilage composition, using magnetic resonance imaging (MRI)-based T2 relaxation time measurements, and structural knee abnormalities. In the Osteoarthritis Initiative 208, participants with DM (age 63.0 ± 8.9 years; 111 females) and risk factors for osteoarthritis (OA) or mild radiographic tibiofemoral OA (Kellgren-Lawrence [KL] grade ≤2) were identified and group-matched with 208 controls without DM (age 63.3 ± 9.1 years; 111 females). Subjects with diabetes-related renal or ophthalmological complications or insulin treatment at baseline (n = 50) were defined as severe DM. 3T MR images of the right knee were assessed for articular cartilage T2 , including texture and laminar analyses derived from the patella, medial, and lateral femur and tibia and for structural abnormalities using the modified whole-organ magnetic resonance imaging score (WORMS). Clustered linear regression analyses were used to assess associations of DM with MRI findings. DM subjects had significantly higher cartilage T2 in the patella (mean difference 0.92 msec [95% confidence interval (CI) 0.79, 1.06]; P = 0.001) and medial femur (mean difference 0.36 msec [95% CI 0.27, 0.81]; P = 0.006) compared to controls. Averaged over all compartments, DM subjects showed significantly higher texture parameters (variance, P = 0.001; contrast, P = 0.002; entropy, P < 0.001). Subjects with severe DM additionally showed higher T2 in the medial tibial deep and superficial layers (P = 0.011 and P = 0.041) compared to controls. No significant differences in cartilage, meniscus, and overall WORMS were found between the groups (P > 0.05). In comparison to nondiabetic controls, cartilage in DM subjects showed higher and more heterogeneous cartilage T2 values, indicating increased articular cartilage degeneration. This affected even more compartments in subjects with severe DM. 2 Technical Efficacy: 5 J. Magn. Reson. Imaging 2018;47:380-390.

Failure of high tibial varus osteotomy for lateral tibio-femoral osteoarthritis with < 10° of valgus: Outcomes in 19 patients

BackgroundOsteotomy is a rational approach to slowing knee osteoarthritis progression by modifying loads, thereby avoiding joint replacement in younger individuals. Varus femoral osteotomy is recommended only in patients with more than 10° of valgus. The objective here was to assess outcomes of tibial varus osteotomy in patients with lateral compartment tibio-femoral osteoarthritis and less than 10° of valgus. The hypothesis was that high tibial varus osteotomy produces satisfactory and long-lasting improvements. Material and methodsA single-centre retrospective study was conducted in 19 consecutive patients managed by high tibial varus osteotomy between January 2005 and May 2012. Mean age was 54.5years. The clinical IKS knee and function scores and radiological parameters were determined pre-operatively then after 6 and 12months and at last follow-up. The primary outcome measure was the global IKS score. Failure was defined as a global IKS score <140 or total knee arthroplasty (TKA). Secondary outcome measures were a post-operative hip-knee-ankle (HKA) angle between 180° and 183° and less than 10° of joint line obliquity. The hypothesis was that high tibial varus osteotomy produced satisfactory and long-lasting improvements in lateral compartment tibio-femoral osteoarthritis. ResultsAfter the mean follow-up of 4.3years (range, 2–9years), 10/19 patients had a global IKS score <140. Among them, 7 underwent TKA after a mean of 5.0±2.7years. Varus tibial osteotomy was followed by significant improvements in the IKS knee and function scores from baseline to last follow-up (P<0.05). A global IKS<140 predicted TKA. Mean HKA angle values were 186.3±2.9° pre-operatively and 181.3°± 3.9°at last follow-up (P<0.05); the HKA angle was within the 180°–183° range in 8 (42.1%) patients. Mean post-operative joint line obliquity was 7.8±3.0°. An HKA angle outside the 180–183° range and joint line obliquity >10° were associated with poor outcomes. DiscussionHigh tibial varus osteotomy produces unsatisfactory medium-term outcomes, with an overall failure rate of 52%. At present, high tibial varus osteotomy has no role in the management of lateral compartment tibio-femoral osteoarthritis with <10° of valgus. Level of evidenceIV, retrospective cohort study.

Synovial fluid pro-inflammatory profile differs according to the characteristics of knee pain.

The role of inflammation and pain in osteoarthritis (OA) is not fully understood. We evaluated the association between pro-inflammatory biomarkers and pain. We used baseline data and samples from a randomized controlled trial of colchicine for symptomatic knee OA. Severity of pain of the more symptomatic knee was assessed by National Health and Nutrition Examination Survey-I (NHANES-I) criterion and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain index. Pains on movement and at rest were self-reported on an 11-point Likert scale. Severity of radiographic tibiofemoral OA was assessed by Kellgren and Lawrence (KL) grade. Concentrations of synovial fluid (sf) IL-1β, IL-6, IL-8, TNFα, C-terminal telopeptides of Type I collagen (CTXI) and C-telopeptide of Type II collagen (CTXII), as well as urinary (u) CTXII were measured. Of the 109 patients enrolled in the study, 70 patients (70% women) with synovial fluid obtained by direct aspiration were included for analysis. The mean±SD age and body mass index (BMI) of the patients were 57.6±8.3 years and 28.8±5.2kg/m2. After adjustment for age, sex, and BMI, sf IL-6 and IL-8 were statistically significantly associated with 11-point pain on movement, but not with pain at rest. No significant associations were observed with WOMAC pain scores. sf IL-1β (analyzed as detectable/non-detectable) was inversely associated with pain. In contrast, after adjustment, Sf TNFα was associated with WOMAC total pain and both pain on movement and at rest. sf/u CTXII was associated with radiographic severity, but not with knee pain. This study provides indication that OA pain mechanisms may differ according to the characteristics of the pain.

Patellofemoral Osteoarthritis does not affect Tolerability of Traditional Therapeutic Exercise in Individuals with Tibiofemoral Osteoarthritis

Patellofemoral Osteoarthritis does not affect Tolerability of Traditional Therapeutic Exercise in Individuals with Tibiofemoral Osteoarthritis

Quadriceps rate of torque development predicts disability in individuals with tibiofemoral knee osteoarthritis

Quadriceps rate of torque development predicts disability in individuals with tibiofemoral knee osteoarthritis

Associations between changes in knee pain location and clinical symptoms in people with medial tibiofemoral osteoarthritis: an exploratory study

Associations between changes in knee pain location and clinical symptoms in people with medial tibiofemoral osteoarthritis: an exploratory study

Do Gait Patterns Differ based on Radiographic Patellofemoral Osteoarthritis Disease Severity in Individuals with Mild Tibiofemoral Osteoarthritis?

Do Gait Patterns Differ based on Radiographic Patellofemoral Osteoarthritis Disease Severity in Individuals with Mild Tibiofemoral Osteoarthritis?

Personalized articulating joint distraction for treatment of tibiofemoral osteoarthritis: clinical feasibility

Personalized articulating joint distraction for treatment of tibiofemoral osteoarthritis: clinical feasibility

Changes in clinical symptoms and functional disability in patients with coexisting patellofemoral and tibiofemoral osteoarthritis: a 1-year prospective cohort study

BackgroundThis 1-year prospective cohort study aimed to compare the changes in clinical symptoms and functional disability between patients with coexisting patellofemoral (PF) and tibiofemoral (TF) osteoarthritis (OA) and those with isolated TFOA.MethodsSeventy-two patients with medial knee OA were enrolled. Knee pain and functional disability were assessed at baseline and at 1-year follow-up using the Japanese Knee Osteoarthritis Measure (JKOM) and a visual analog scale (VAS). We performed two-way analysis of covariance for the clinical outcome variables to examine, time (baseline and follow-up), group (coexisting PFOA and isolated TFOA), and time-group interaction effects. Furthermore, we conducted post-hoc exploratory analysis to address the possibility that dividing patients according to location of PFOA (i.e., isolated lateral, isolated medial, and mixed [bilateral]) may identify a distinct subgroup with different changes in clinical outcomes at 1-year follow-up.ResultsWe detected group effects only in scores of the JKOM pain subscale (P = 0.012) and VAS (P = 0.033), adjusted for age, sex, and body mass index. Patients with coexisting PFOA have stable moderate level knee pain and functional disability throughout the year which is significantly worse than that in those with isolated TFOA. Post-hoc subgroup analysis demonstrated that change of knee pain likely varied with location of PFOA. Patients with isolated lateral PFOA had mild/moderate level knee pain, and their VAS scores were likely to improve, whereas those with mixed PFOA exhibited stable to worsening moderate/severe knee pain.ConclusionsAlthough we did not detect differences in changes in clinical symptoms and functional disability between patients with coexisting PFOA and those with isolated TFOA, our findings indicate that patients with coexisting PFOA had worse clinical symptoms and functional disability than those with isolated TFOA. The results of the exploratory analysis suggested that patients with coexisting PFOA might have heterogeneous clinical outcomes, and presence of mixed PFOA might be an indicator of severe clinical knee OA.

Associations between changes in knee pain location and clinical symptoms in people with medial knee osteoarthritis using footwear for self-management: an exploratory study.

To examine whether change in pain location is associated with clinically-relevant improvements in walking pain severity and physical dysfunction in people with medial tibiofemoral osteoarthritis (OA) using footwear for self-management. We analysed a sub-set of 91 participants pooled from both arms of a 6-month randomised controlled trial of footwear for knee OA. The Photographic Knee Pain Map was self-administered to generate changes in the number of painful zones ('unchanged', 'increased', 'decreased') and anatomical patterns of pain ('unchanged', 'no longer diffuse', 'becoming diffuse', 'other pattern changes'). Improvement in symptoms was determined using the minimum clinically important differences (MCIDs) in pain severity on a numeric rating scale, and function with the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Fisher's exact tests examined differences in symptom improvement across categories of change and odds ratios (ORs, 95% CI) were calculated (adjusted for treatment allocation). Seventy-four percent (n=67) of participants reported a change in pain location, and 46-50% (n=42-45) reported clinically-relevant improvements in pain and function respectively. Fewer participants 'becoming diffuse' reported improved pain (n=0, 0%) when compared to the other pattern change categories (P=0.012). Participants with 'no longer diffuse' (OR (95% CI)=0.3 (0.1-0.9) or 'becoming diffuse' (OR (95% CI)=0.0 (0.0-0.4) pain patterns had significantly lower odds of improved function than those with 'other pattern changes'. Participants either developing into, or changing from, diffuse pain patterns were less likely to experience improvement in pain and/or function when self-managing with footwear.

Dynamic Balance Training Improves Physical Function in Individuals With Knee Osteoarthritis: A Pilot Randomized Controlled Trial

ObjectiveTo examine the effect of a targeted balance training program on dynamic balance and self-reported physical function in people with medial tibiofemoral osteoarthritis (OA). DesignSingle-blind randomized controlled trial. SettingExercise gymnasium and community dwellings. ParticipantsIndividuals with medial compartment knee OA (N=40). InterventionsTen weeks of partially supervised exercises targeting dynamic balance and strength performed 4 times per week or no intervention (nonintervention group). Main Outcome MeasuresDynamic balance was measured using the Community Balance and Mobility Scale (CB&M), and self-reported physical function was measured using the Western Ontario and McMaster Universities Arthritis Index physical function subscale. Secondary outcomes included knee pain, fear of movement, knee joint proprioception, and muscle strength. ResultsForty individuals underwent baseline testing, with 36 participants completing follow-up testing. Adherence to exercise in the training group was high, with 82.2% of all home-based exercise sessions completed. No significant changes were observed in any outcome in the nonintervention group at follow-up. Significant improvements in self-reported pain, physical function, and fear of movement were observed in the training group when compared with the nonintervention group. No other within- or between-group differences were observed. ConclusionsA 10-week dynamic balance training program for people with knee OA significantly improved self-reported knee pain, physical function, and fear of movement; however, there was no change in dynamic balance as quantified by the CB&M. Further research is needed to investigate how exercise may result in improvement on objective measures of dynamic balance.

Impact of Cane Use on Bone Marrow Lesion Volume in People With Medial Knee Osteoarthritis (CUBA Trial).

No effective cure exists for knee osteoarthritis (OA). Low-burden self-management strategies that can slow disease progression are needed. Bone marrow lesions (BMLs) are a source of knee pain and accelerate cartilage loss. Importantly, they may be responsive to biomechanical off-loading treatments. The study objective is to investigate whether, in people with medial tibiofemoral OA, daily cane use for 12 weeks reduces the volume of medial tibiofemoral BMLs and improves pain, physical function, and health-related quality of life. This study will be an assessor-masked, 2-arm, parallel-group, multisite randomized controlled trial. The community will serve as the setting for this study. The study participants will be people who are 50 years old or older and have medial tibiofemoral OA and at least 1 medial tibiofemoral BML. The participants will be allocated to either the cane group (using a cane daily whenever walking for 12 weeks) or the control group (not using any gait aid for 12weeks). Outcomes will be measured at baseline and 13 weeks. The primary outcome will be total medial tibiofemoral BML volume measured from magnetic resonance imaging. Secondary outcomes will include BML volume of the medial tibia and/or femur, knee pain overall and on walking, physical function, participant-perceived global change, and health-related quality of life. Additional measures will include physical activity, cointerventions, adverse events, participation, participant demographics, cane training process measures and feasibility, barriers to and facilitators of cane use, and loss to follow-up. People who are morbidly obese will not be included because of difficulties with magnetic resonance imaging. The findings of this study will help to determine whether cane use can alter disease progression in people with medial tibiofemoral OA and/or influence clinical symptoms. This study may directly influence clinical guidelines for the management of knee OA.

Genome-Wide Association Study of Radiographic Knee Osteoarthritis in North American Caucasians.

A major barrier to genetic studies of osteoarthritis (OA) is the need to obtain large numbers of individuals with standardized radiographic evaluations for OA. To address this gap, we performed a genome-wide association study (GWAS) of radiographically defined tibiofemoral knee OA in 3,898 cases and 3,168 controls from 4 well-characterized North American cohorts, and we performed replication analysis of previously reported OA loci. We performed meta-analysis using a 2-stage design. Stage 1 (discovery) consisted of a GWAS meta-analysis of radiographic knee OA carried out in the Osteoarthritis Initiative and the Johnston County Osteoarthritis Project. Knee OA was defined as definite osteophytes and possible joint space narrowing or total joint replacement in one or both knees. Stage 2 (validation) was performed in the Multicenter Osteoarthritis Study and the Genetics of Osteoarthritis study. We genotyped lead meta-analysis variants (P ≤ 1 × 10-4 ) from stage 1 and tested the association between these variants and knee OA. We then combined results from all cohorts in a meta-analysis. Lead variants from stage 1, representing 49 unique loci, were analyzed in stage 2; none met genome-wide significance in the combined analysis of stage 1 and stage 2. We validated 1 locus (rs4867568 near LSP1P3) with nominal significance (P < 0.05), which was also our top finding in the combined meta-analysis (odds ratio [OR] 0.84 [95% confidence interval (95% CI) 0.79-0.91], P = 3.02 × 10-6 ). We observed nominally significant associations (P < 0.05) with 3 previously reported OA loci: rs143383 in GDF5 (OR 1.12 [95% CI 1.04-1.21], P = 2.13 × 10-3 ), rs835487 in CHST11 (OR 0.93 [95% CI 0.85-0.99], P = 0.03), and rs8044769 in FTO (OR 1.10 [95% CI 1.03-1.19], P = 6.13 × 10-3 ). These findings provide suggestive evidence of a novel knee OA locus and confirm previously reported associations in GDF5, CHST11, and FTO.

Can three-dimensional patient-specific cutting guides be used to achieve optimal correction for high tibial osteotomy? Pilot study

IntroductionTreatment of medial tibiofemoral osteoarthritis with a high-tibial osteotomy (HTO) is most effective when the optimal angular correction is achieved. However, conventional instrumentation is limited when multiplanar correction is needed. HypothesisUse of patient-specific cutting guides (PSCGs) for HTO provides an accurate correction (difference<2°) relative to the preoperative planning. Materials and methodsBetween February 2014 and February 2015, 10 patients (mean age: 46 years [range: 31–59]; grade 1 or 2 osteoarthritis in Ahlbäck's classification) were included prospectively in this reliability and safety study. All patients were operated using the same medial opening-wedge osteotomy technique. Preoperative planning was based on long-leg radiographs and CT scans with 3D reconstruction. The PSGCs were used to align the osteotomy cut and position the screw holes for the plate. The desired correction was achieved in the three planes when the holes on the plate were aligned with the holes drilled based on the PSCG. Preoperatively, the mean HKA angle was 171.9° (range: 166–179°), the mean proximal tibial angle was 87° (86–88°) and the mean tibial slope was 7.8° (1–22°). The postoperative correction was compared to the planned correction using 3D CT scan transformations. Intraoperative and postoperative complications were assessed at a minimum follow-up of 1 year. ResultsThe procedure was successfully carried out in all patients with the PSCGs. On postoperative long-leg radiographs, the mean HKA was 182.3° (180–185°); on the CT scan, the mean tibial mechanical angle was 94° (90–98°) and the mean tibial slope was 7.1° (4–11°). In 19 out of 20 postoperative HKA and slope measurements, the difference between the planned and achieved correction was <2° based on the 3D analysis of the three planes in space; in the other case, the slope was 13° instead of the planned 10°. The intra-class correlation coefficients between the postoperative and planned parameters were 0.98 [0.92–0.99] for the HKA and 0.96 [0.79–0.99] for the tibial slope. There were no surgical site infections; one patient had a postoperative hematoma that resolved spontaneously. DiscussionThe results of this study showed that use of PSCGs in HTO procedures helps to achieve optimal correction in a safe and reliable manner. Level of evidenceIV – Prospective cohort study.

Pain prediction by serum biomarkers of bone turnover in people with knee osteoarthritis: an observational study of TRAcP5b and cathepsin K in OA

To investigate serum biomarkers, tartrate resistant acid phosphatase 5b (TRAcP5b) and cathepsin K (cath-K), indicative of osteoclastic bone resorption, and their relationship to pain and pain change in knee osteoarthritis (OA). Sera and clinical data were collected from 129 people (97 with 3-year follow-up) with knee OA from the Prediction of Osteoarthritis Progression (POP) cohort. Knee OA-related outcomes in POP included: WOMAC pain, National Health and Nutrition Examination Survey (NHANES) I (pain, aching and stiffness), subchondral sclerosis, and radiographically determined tibiofemoral and patellofemoral OA. Two putative osteoclast biomarkers were measured in sera: TRAcP5b and cath-K. Medial tibia plateaux were donated at knee arthroplasty for symptomatic OA (n=84) or from 16 post mortem (PM) controls from the Arthritis Research UK (ARUK) Pain Centre joint tissue repository. Osteoclasts were stained for tartrate resistant acid phosphatase (TRAcP) within the subchondral bone of the medial tibia plateaux. Serum TRAcP5b activity, but not cath-K-immunoreactivity, was associated with density of TRAcP-positive osteoclasts in the subchondral bone of medial tibia plateaux. TRAcP-positive osteoclasts were more abundant in people with symptomatic OA compared to controls. Serum TRAcP5b activity was associated with baseline pain and pain change. Our observations support a role for subchondral osteoclast activity in the generation of OA pain. Serum TRAcP5b might be a clinically relevant biomarker of disease activity in OA.

Lateral wedges with and without custom arch support for people with medial knee osteoarthritis and pronated feet: an exploratory randomized crossover study

BackgroundPronated foot posture is associated with many clinical and biomechanical outcomes unique to medial compartment knee osteoarthritis (OA). Though shoe-worn insole treatment, including lateral wedges, is commonly studied in this patient population, their effects on the specific subgroup of people with medial knee OA and concomitant pronated feet are unknown. The purpose of this study was to evaluate whether lateral wedge insoles with custom arch support are more beneficial than lateral wedge insoles alone for knee and foot symptoms in people with medial tibiofemoral knee osteoarthritis (OA) and pronated feet.MethodsTwenty-six people with pronated feet and symptomatic medial knee OA participated in a randomized crossover study comparing five degree lateral wedge foot insoles with and without custom foot arch support. Each intervention was worn for two months, separated by a two-month washout period of no insoles wear. Main outcomes included the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain and physical function subscales, the revised short-form Foot Function Index (FFI-R) pain and stiffness subscales, and the timed stair climb test. Regression modeling was conducted to examine treatment, period, and interaction effects.ResultsTwenty-two participants completed the study, and no carryover or interaction effects were observed for any outcome. Significant treatment effects were observed for the timed stair climb, with greater improvements seen with the lateral wedges with arch support. Within-condition significant improvements were observed for WOMAC pain and physical function, as well as FFI-R pain and stiffness with lateral wedges with arch support use. More adverse effects were reported with the lateral wedges alone, while more people preferred the lateral wedges with arch support overall.ConclusionsAddition of custom arch support to a standard lateral wedge insole may improve foot and knee symptoms in people with knee OA and concomitant pronated feet. These preliminary findings suggest further research evaluating the role of shoe-worn insoles for treatment of this specific sub-group of people with knee OA is warranted.Trial registrationClinicaltrials.gov identifier: NCT02234895.